Unimportant

Probably a power supply problem. The degaussing you hear is handled via a posistor and works even with a broken power supply.

Hi! I just wanted to talk about something that grinds my ears and that is emission standards. My b5 passat gets an impressive 4.3l/100km combined, but it's only rated at euro2 emissions. Now why my neighbour with a new car burn 2 times as much fuel and still be fine, because it's an euro6. Even if it polutes less per l of burnt diesel, it burns twice as much. And let's say the dpf makes up for the aditional burnt fuel in terms of emissions, burning twice as much fuel means that car exhausts the limited amout of oil in the earth twice as fast, and trucks need to deliver the fuel twice as often. What do you think?

The function keys are often used in debuggers for "step over", "step into", etc. You'll probably spend a lot of time in a debugger so ...

A ultra cheap way we've utilized before and works well is to buy the cheapest POS 3$ USB keyboard you can find and rip it apart to take the controller board out. Then find a couple - nonblocking - inputs on the multiplex to attach your buttons to.

Probably a power supply problem. The degaussing you hear is handled via a posistor and works even with a broken power supply.

4kHz is fine, nothing to worry about.
 

For the act of programming itself, not so much. You're basically working in a glorified text editor, something PC's 30 years ago could handle. Compiling huge projects can take a while, but is more disk related, as you're dealing with lots of small files (A SSD will help much more then a better CPU).
 
Debugging is very user limited. You're basically stepping trough the code while looking at variables and trying to figure out what's happening. The computer is waiting on you here, not the other way around.
 
As for running the program you're making. It depends. A tiny program that runs a critical loop can benefit greatly from a faster CPU while a large linear program will see no difference whatsoever.
It all comes down to loops. Even a pentium1 will run trough tens of thousands of lines a code in a second, but a loop can take ages depending on what it does. A faster CPU can potentially help there, but in most cases loops are slow because they're written in a cache unfriendly way. A loop with lots of cache misses will be slow on any CPU.
 
For the beginning programmer it'll probably make no difference.
 
 

It's a markup language, that's what the "ML" stands for

Mainly because of government guaranteed loans.
 
Because of government guaranteed loans, students can borrow vast amounts of money they would not have been able to borrow otherwise. No lender would be crazy enough to lend so much money to a young person who hasn't even done the first thing in proving ever being able to pay it back absent government guarantees.
 
Students then turn around and bid the price up using that money. It's a vicious circle. If students weren't able to borrow so much money many of them would not be able to afford to go to college and colleges would have to slash prices to keep their seats filled up. But because the guarantees have driven prices up so high it looks to most ppl as if the guarantees are necessary and a good thing rather then the main cause of the problem.
 
A secondary reason is also the current mentality that everyone has to go to college. Standards have been lowered and ridiculous, completely useless, courses have been added to allow more people to make the cut, which adds to demand and drives prices up.
But many ppl just aren't college material and it's a waste of everyone's time and money forcing them trough a dumbed down useless course anyway.
 
 

Simpler implementation of that logic:
 
#include <iostream> #include <string> using namespace std; int main() { const auto numLines = 10; for (int i = 0; i < numLines; ++i) { cout << string(numLines - i - 1, ' ') << string(i * 2 + 1 , '*') << '\n'; } return 0; }  

Mainly because of government guaranteed loans.
 
Because of government guaranteed loans, students can borrow vast amounts of money they would not have been able to borrow otherwise. No lender would be crazy enough to lend so much money to a young person who hasn't even done the first thing in proving ever being able to pay it back absent government guarantees.
 
Students then turn around and bid the price up using that money. It's a vicious circle. If students weren't able to borrow so much money many of them would not be able to afford to go to college and colleges would have to slash prices to keep their seats filled up. But because the guarantees have driven prices up so high it looks to most ppl as if the guarantees are necessary and a good thing rather then the main cause of the problem.
 
A secondary reason is also the current mentality that everyone has to go to college. Standards have been lowered and ridiculous, completely useless, courses have been added to allow more people to make the cut, which adds to demand and drives prices up.
But many ppl just aren't college material and it's a waste of everyone's time and money forcing them trough a dumbed down useless course anyway.
 
 

Mainly because of government guaranteed loans.
 
Because of government guaranteed loans, students can borrow vast amounts of money they would not have been able to borrow otherwise. No lender would be crazy enough to lend so much money to a young person who hasn't even done the first thing in proving ever being able to pay it back absent government guarantees.
 
Students then turn around and bid the price up using that money. It's a vicious circle. If students weren't able to borrow so much money many of them would not be able to afford to go to college and colleges would have to slash prices to keep their seats filled up. But because the guarantees have driven prices up so high it looks to most ppl as if the guarantees are necessary and a good thing rather then the main cause of the problem.
 
A secondary reason is also the current mentality that everyone has to go to college. Standards have been lowered and ridiculous, completely useless, courses have been added to allow more people to make the cut, which adds to demand and drives prices up.
But many ppl just aren't college material and it's a waste of everyone's time and money forcing them trough a dumbed down useless course anyway.
 
 

Mainly because of government guaranteed loans.
 
Because of government guaranteed loans, students can borrow vast amounts of money they would not have been able to borrow otherwise. No lender would be crazy enough to lend so much money to a young person who hasn't even done the first thing in proving ever being able to pay it back absent government guarantees.
 
Students then turn around and bid the price up using that money. It's a vicious circle. If students weren't able to borrow so much money many of them would not be able to afford to go to college and colleges would have to slash prices to keep their seats filled up. But because the guarantees have driven prices up so high it looks to most ppl as if the guarantees are necessary and a good thing rather then the main cause of the problem.
 
A secondary reason is also the current mentality that everyone has to go to college. Standards have been lowered and ridiculous, completely useless, courses have been added to allow more people to make the cut, which adds to demand and drives prices up.
But many ppl just aren't college material and it's a waste of everyone's time and money forcing them trough a dumbed down useless course anyway.
 
 

Mainly because of government guaranteed loans.
 
Because of government guaranteed loans, students can borrow vast amounts of money they would not have been able to borrow otherwise. No lender would be crazy enough to lend so much money to a young person who hasn't even done the first thing in proving ever being able to pay it back absent government guarantees.
 
Students then turn around and bid the price up using that money. It's a vicious circle. If students weren't able to borrow so much money many of them would not be able to afford to go to college and colleges would have to slash prices to keep their seats filled up. But because the guarantees have driven prices up so high it looks to most ppl as if the guarantees are necessary and a good thing rather then the main cause of the problem.
 
A secondary reason is also the current mentality that everyone has to go to college. Standards have been lowered and ridiculous, completely useless, courses have been added to allow more people to make the cut, which adds to demand and drives prices up.
But many ppl just aren't college material and it's a waste of everyone's time and money forcing them trough a dumbed down useless course anyway.
 
 

Mainly because of government guaranteed loans.
 
Because of government guaranteed loans, students can borrow vast amounts of money they would not have been able to borrow otherwise. No lender would be crazy enough to lend so much money to a young person who hasn't even done the first thing in proving ever being able to pay it back absent government guarantees.
 
Students then turn around and bid the price up using that money. It's a vicious circle. If students weren't able to borrow so much money many of them would not be able to afford to go to college and colleges would have to slash prices to keep their seats filled up. But because the guarantees have driven prices up so high it looks to most ppl as if the guarantees are necessary and a good thing rather then the main cause of the problem.
 
A secondary reason is also the current mentality that everyone has to go to college. Standards have been lowered and ridiculous, completely useless, courses have been added to allow more people to make the cut, which adds to demand and drives prices up.
But many ppl just aren't college material and it's a waste of everyone's time and money forcing them trough a dumbed down useless course anyway.
 
 

Mainly because of government guaranteed loans.
 
Because of government guaranteed loans, students can borrow vast amounts of money they would not have been able to borrow otherwise. No lender would be crazy enough to lend so much money to a young person who hasn't even done the first thing in proving ever being able to pay it back absent government guarantees.
 
Students then turn around and bid the price up using that money. It's a vicious circle. If students weren't able to borrow so much money many of them would not be able to afford to go to college and colleges would have to slash prices to keep their seats filled up. But because the guarantees have driven prices up so high it looks to most ppl as if the guarantees are necessary and a good thing rather then the main cause of the problem.
 
A secondary reason is also the current mentality that everyone has to go to college. Standards have been lowered and ridiculous, completely useless, courses have been added to allow more people to make the cut, which adds to demand and drives prices up.
But many ppl just aren't college material and it's a waste of everyone's time and money forcing them trough a dumbed down useless course anyway.
 
 

Use a hair dryer to blow hot air from the opposite side of the circuit board and heat up the pcb, making it easier to solder.
Use leaded solder, as it melts at lower temperature (180-183c vs 217c for lead free solder) .. combining with the existing lead free solder will cause melting temp. to lower
USE LIQUID FLUX ... it's like magic... the existing solder may have a layer of oxide on it which will basically act as a heat shield and will reduce the flow of heat from your soldering iron.
In theory new solder has a flux core inside which would help but it's often not enough. Often a drop or two of flux where you'll add solder will break those oxides and help the soldering iron tip break through and transfer heat into the area more efficiently

No, see my post above.
 
Even the comity and Bjarne Stroustrup have repeatedly admitted the STL got it wrong when they used unsigned for subscripts and sizes. (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1428r0.pdf)
 
 

The Siglent SDS1204X-E comes in at the upper end of your budget (659€ excl. VAT RSP, but you can find deals), and ticks most of your boxes.
7", 4 channel (2x2 shared), 200Mhz, 1GSa/s, FFT and SPI/I2C decoding.
It does not have a function generator but I'd buy a separate device for that anyway.
Also does not have a VGA/HDMI output. I don't think any of the affordable devices do, but it does have a built-in web host that allows visiting the scope's "web page" from any PC connected to the network and control/view it.
 
We've got a couple of those in the lab as daily drivers to free up the expensive stuff and I can't really fault it for the price.
 

I've hundreds of second hand 18650 cells pulled from laptops, cordless drills, etc...
 
Their wear levels are all over the place and even tough I try to select cells that test at similar capacities to make a battery pack I find that most commercial balancer solutions simply refuse to charge such dissimilar cells.
 
So I designed this. It charges all the cells in series and each cell has a bypass transistor parallel to it (on the bottom of the board on a heatsink). The bypass transistor starts conducting at 4,15V and shunts the charging current around the cell, preventing it from going over 4,15V while the other cells continue charging. When all cells are bypassed the battery pack is full.
 
It also does not charge if any cell is below 2V unloaded (damaged cell safety) or reversed polarity.

I've hundreds of second hand 18650 cells pulled from laptops, cordless drills, etc...
 
Their wear levels are all over the place and even tough I try to select cells that test at similar capacities to make a battery pack I find that most commercial balancer solutions simply refuse to charge such dissimilar cells.
 
So I designed this. It charges all the cells in series and each cell has a bypass transistor parallel to it (on the bottom of the board on a heatsink). The bypass transistor starts conducting at 4,15V and shunts the charging current around the cell, preventing it from going over 4,15V while the other cells continue charging. When all cells are bypassed the battery pack is full.
 
It also does not charge if any cell is below 2V unloaded (damaged cell safety) or reversed polarity.

But not a single PSU has a overcurrent protection that trips at that low a current.
Overcurrent protection/Fuses are mainly meant to protect the wiring against overcurrent. The safe bet is to use wire that can at least handle the trip current of the PSU.

@Hi P Many clean code guidelines/techniques can be applied to any language. Of course it depends on the language paradigm. Object oriented techniques obviously can't be applied to a functional only language. (And attempting to mimic them is one source of ugly code).
 
That said, one should probably try to get books that apply to a language you know pretty well so you can understand the examples laid out in the book.
 
Also don't overlook the wealth of free information in the form of talks on youtube. In the C++ world you've got the CppCon channel, "Going native" and "clean code talks", for example.

@Hi P Many clean code guidelines/techniques can be applied to any language. Of course it depends on the language paradigm. Object oriented techniques obviously can't be applied to a functional only language. (And attempting to mimic them is one source of ugly code).
 
That said, one should probably try to get books that apply to a language you know pretty well so you can understand the examples laid out in the book.
 
Also don't overlook the wealth of free information in the form of talks on youtube. In the C++ world you've got the CppCon channel, "Going native" and "clean code talks", for example.

Aggressive Lithium Ion series balance charger. Charges up to 4 Li-Ion cells in series no matter how unbalanced/different the batteries are:

 
Class D-Amplifier power stage prototype meant to mate with easily swappable PWM stage prototypes for development purposes:
This is the third iteration and I'm pretty stoked about the fact that this thing hardly radiates despite 15nS transistion times @ 50V upto 10A.

 
All my other PCB's I've currently on the bench are work related and not allowed to show